1. Field of the Invention
The present invention relates to a cooling device for a battery module and to a battery device.
2. Description of the Background Art
High-performance energy storage devices such as, for example, Li-ion or NiMH accumulators or supercaps are used in modern hybrid electric and electric vehicles (HEV/EV) vehicles. Heating occurs in these during rapid charging and discharging due to resistances within and outside the cells. Temperatures above 50° C. damage the energy storage devices permanently. To assure the function of the energy storage devices, they must be actively cooled. For this purpose, the energy storage devices are brought into thermal contact with a special cooler. In other words, all cells should be at the same temperature level. The temperature level of the cells influences their lifetime and the output and thereby critically the lifetime of the entire battery.
For optimal operation of the cooling function, it is important that the cooler has a thermal contact as uniform as possible at each cell or each battery module. Among other things, a uniform pressing force is necessary for this. These pressing forces must also be present to a still sufficient extent years later with different vibrations, changes in load, material fatigue, temperature effects, subsidence phenomena, etc. Springs are often used structurally for this purpose.
Springs are used in this regard so that individual or a number of cooling plates or battery cells can be tensioned or pressed by means of a spring onto a cooling plate. DE 10 2009 058 070 A1, for example, describes a vertical bracing of a battery stack.